The insulated wires for equipments, such as lead wire for motors, wires for vehicles, wires for automobiles and particularly wires for automobiles which are to be used near an engine are requested to have high resistance to heat, abrasion and oil, as well as superior cut-through property. To illustrate heat resistance, an insulated wire for equipments which poses no practical problem in terms of mechanical properties and electrical properties even after an aging test at 200.degree. C. for 40,000 hours is demanded. Conventionally, there are insulated wires for use for equipments, which are manufactured by using fluorocarbon resins such as PTFE (polytetrafluoroethylene), PFA (tetrafluoroethylene-perfluoroalkoxy copolymer), FEP (tetrafluoroethylene-hexafluoropropylene copolymer), ETFE (ethylene-tetrafluoroethylene copolymer) and the like for forming an insulating layer of such wires.
Incidentally, along with the recent miniaturization of equipments and appratuses, the above-mentioned wires for equipments are also required to have, besides the essential properties as recited above, flexibility so as to enable efficient wiring thereof in a narrow space. Despite such requirement, insulated wires having an insulating layer prepared by the use of the aforementioned fluorocarbon resins are poor in flexibility and efficient installing of said wires in a narrow space within the miniaturized equipments is not attainable, also posing difficulty in workability when wiring.
While there has been an insulated wire having an insulating layer prepared by the use of a fluorocarbon rubber, it is susceptible to inferior resistance to abrasion and poor cut-through property. In addition, there has been proposed an insulating composition comprising ethylene-tetrafluoroethylene copolymer and tetrafluoroethylene-propylene copolymer (Japanese Patent Unexamined Publication No. 123444/1977).